Petrol vs Diesel vs Electric Running Costs in Ireland (May 2026): Cost per km Compared

At May 2026 prices, petrol costs 12.7c/km, diesel 10.8c/km, and an EV on home night rate just 1.5c/km. Full per-km and annual cost breakdown — updated with the latest AA Ireland fuel prices.

EV Charging · Updated 14 May 2026
ev ireland running-costs petrol diesel

Fuel prices in Ireland have eased for a second month since the April excise cuts and the wholesale oil price peak. The relief is real but temporary — the underlying running cost gap between petrol, diesel, and electric still matters, and only widens when the cuts expire in July.

This guide gives you the actual numbers: what each fuel type costs per kilometre at today’s prices, what happens when the excise cuts expire on 31 July, and how the economics of electric vehicles compare at today’s prices and at pre-cut prices.

What fuel prices look like right now

The May 2026 AA Ireland fuel price survey (published 14 May) shows further easing after April’s excise cuts and a softer wholesale oil market.

Average pump prices by phase, 2026:

FuelPre-March (peak)Post-March cutsPost-April cutsMay 2026 (current)
Petrol (95 unleaded)~€2.05/litre~€1.90/litre~€1.91/litre€1.82/litre
Diesel~€2.36/litre~€2.16/litre~€2.14/litre€1.97/litre

The total excise reduction since March is 27 cent per litre on petrol and 32 cent per litre on diesel — that relief is still in place.

These cuts are temporary. The government’s current package runs to 31 July 2026. The carbon tax increase has been deferred to the October budget, but no commitment has been made to extend the excise reductions beyond July. See the full Ireland fuel prices guide for the timeline and policy detail.

What this means in practice: If you are making a car purchase decision based on fuel costs, use the pre-cut prices as your planning baseline — they are closer to where prices will return.

Cost per 100km: the actual comparison

The numbers below use real-world consumption figures for typical Irish cars, not manufacturer test-cycle figures.

Assumptions:

  • Petrol car: 7.0 litres per 100km (typical mid-size hatchback in mixed driving)
  • Diesel car: 5.5 litres per 100km (same class)
  • Electric car: 17 kWh per 100km (typical for a mid-range EV such as a Volkswagen ID.4 or Hyundai Ioniq 5)
  • EV home night rate: 9 cent per kWh (representative of current EV-specific tariffs in Ireland)
  • EV home standard rate: 35 cent per kWh
  • ESB public fast charger: 45 cent per kWh
  • ESB public rapid charger: 55 cent per kWh

At current May 2026 prices

Fuel typeCost per 100kmCost per km
Petrol€12.7412.7c
Diesel€10.8410.8c
EV — home night rate€1.531.5c
EV — home standard rate€5.956.0c
EV — public fast charger€7.657.7c
EV — public rapid charger€9.359.4c

At pre-protest prices (planning baseline)

Fuel typeCost per 100kmCost per km
Petrol€14.3514.4c
Diesel€12.9813.0c
EV — home night rate€1.531.5c
EV — home standard rate€5.956.0c

EV charging costs are unaffected by the oil price situation — electricity wholesale costs have not followed oil in this cycle.

Annual running cost comparison

Based on 15,000km per year — a typical Irish driver covering commuting and occasional longer trips.

ScenarioAnnual fuel/charging cost
Petrol (May 2026 prices)€1,911
Petrol (post-July baseline)€2,154
Diesel (May 2026 prices)€1,626
Diesel (post-July baseline)€1,950
EV — home night rate only€230
EV — 80% home night, 20% public fast€413
EV — home standard rate only€893

The EV night rate figure assumes you have off-street parking and a home charger. If you rely primarily on public charging, costs rise — but even at fully public charging rates, an EV remains cheaper per kilometre than petrol or diesel.

What changes after July 2026

When the excise duty cuts expire on 31 July 2026, pump prices are expected to return toward the pre-cut levels unless the government takes further action. The carbon tax is also due to increase in the October budget.

For a petrol driver covering 15,000km per year, the expiry of the current cuts represents an annual cost increase of roughly €240 compared to today, and around €325 for a diesel driver.

For an EV driver, nothing changes. EV charging costs are not affected by the July excise expiry.

The purchase price gap

The running cost advantage of an EV is real, but EVs typically cost more to buy upfront than equivalent petrol or diesel cars.

The relevant Irish supports in 2026:

  • SEAI EV purchase grant: up to €3,500 on eligible new EVs (check current SEAI terms — grants and eligible models change)
  • VRT relief: up to €5,000 for BEVs (subject to vehicle price caps)
  • Home charger grant: up to €600 towards installation of a home EV charger

At current running cost differentials, an EV driver saving €1,680 per year on fuel compared to a petrol car recovers a €10,000 purchase premium in roughly 6 years at May 2026 prices — and closer to 5 years once the July excise cuts expire.

Diesel: still worth it?

Diesel made sense for high-mileage drivers when diesel fuel was cheaper and diesel cars were significantly more efficient. That equation has shifted:

  • Diesel fuel now costs more per litre than petrol in Ireland
  • Modern petrol engines have closed much of the efficiency gap
  • Diesel cars carry higher servicing costs (DPF maintenance, AdBlue)
  • Older diesel vehicles face increasing access restrictions in European cities
  • VRT and road tax structures in Ireland no longer strongly favour diesel

For most Irish drivers not covering very high annual mileage (above 25,000km), the case for a new diesel car over a comparable petrol is weak. The case for a new diesel over a comparable EV is weaker still.

Note on prices: Fuel prices change frequently. The figures above reflect the AA Ireland fuel price survey published 14 May 2026. Check the AA Ireland fuel price tracker for current pump prices and ESB ecars price plans for current public charging rates.